Vent mechanism



-March 23, 1937.

- ELR. GIESEMAN 2,074,329

- VENT MECHANISM Filed Sept. 50 1935 INVENTOR EARL 1Q. 6/ESEM4/V Patented Mar. 23, 1937 UNITED STATES PATENT- OFFICE (Granted under the act or March 3, 1883, as amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon. v

My invention relates to vent mechanisms for storage batteries and more particularly to vent plugs which permit the escape of gases from storage batteries but prevent the escape of liquid therefrom.

if) The primary object of the invention is to provide a means that will operate rapidly and positively to prevent leakage of electrolyte from the battery when the same is laid upon its side, is tilted to a lesser extent, or is completely inverted.

1.3 It is a further object of the invention to provide a means which will equally positively vent the aforesaid battery upon return of the same to upright position from the tilted or inverted positions referred to above.

With the foregoing and other objects in view,

sealing element, with tilting the vent mechanism body cap 2 is also provided with a vent hole H),

at right angles to Fig; 1; Fig. 3 is a section taken on the line 33 of Fig. 1, with the sealing element removed; and

Fig. 4 is an enlarged perspective view of the sealing element.

With the advent of aircraft serious need developed for a vent plug possessing the above stated characteristics. Appreciating this need, I entered upon the design, construction and test of a considerable series of vent plugs. I ployed a conical sealing element (of altitude approximating half base diameter) enclosed within an upside down conical cavity (of like slope but greater altitude) having a small vent hole in the base andin the vertex thereof. With tilting of a battery sidewise, this sealing element readily closed the base vent opening of the cell supporting it, but upon return of the battery to' normal, the contacting surfaces of the sealing element remain wedged between the contacted surfaces of the base and wall ofv the upside down conical cavity, thus preventing gas escapage from the battery cell.

Further sealing elements were constructed with cylindrical portions projecting from the conical bases. The upside down conical housings provided for the above also had cylindrical portions slightly less in length than the cylindrical portions of the sealing elements. The sealing elements still remained wedged, upon return of the battery to normal, thus preventing gas escapage resisting material, housing a sealing .element or valve 3 of lead or other acid resisting metal. The plug body I is provided with external threads 4 for mounting the plug assembly upon a battery cell and internal threads 5 for receiving and holding the body cap 2. A cylindrical cavity 6 extends downwardly from the base of the threads 5 a distance approximately one third of its diameter. From the base of the cylindrical cavity 6 an upside down conical cavity 1 terminates with its projected vertex within a vent hole 8 provided in the bottom of the plug body I. Two oppositely disposed grooves 9 connect the vent hole 8 with the cylindrical cavity 6 at all times. The last-named are well shown in Fig. 3. The

external threads H and a milled slot I! for screwing the same fast to the plug body 1.

There remains to be considered the sealing element or valve 3, which is comprised of a cylindrical portion I3 and a truncated conical portion I4. A carefully worked out relationship between the size, and shape of the last-named portions and the size and shape of the cavity configuration of the plug body I and body cap 2 must be maintained if return of the valve 3 to its non-sealed position is to be assured with return of the battery to normal upright position. Further, the location of the center of mass of the valve 3 is a material factor in insuring that the sealing element will slide into a position closing the vent hole It! without upset and therefore with a minimum of resistance. It is readily obvious from an inspection of Fig. 2 that too far forward (i. e., right hand) location of the center of mass will cause clockwise upset of the valve The portion i4 is constructed such that the altitude of its projected cone substantially equals its base diameter. The portion I3 is constructed such that its altitude approximates one third of its base diameter. d1 (cone diameter) equals hi (projected cone height) equals "(12" (cylinder diameter). Also, h-z" (cylinder height) equals one third d1" or hi or d2. Since the volumes of portions 13 and I4 are substantially equal, since the center of mass of the portion I4 is located approximately %hi or, in common diameter terms, M d away from its base, and since the center of mass of the portion I3 is located h or, in common diameter terms; /;d away from its common junction with the portion it, it must follow that the combined center of mass of the portions l3 and I4 lies within portion E4 in very close proximity to the plane of their common junction. It is further important that the cylindrical cavity 6 be of a diameter which will permit free sliding movement of the valve 3 as well as free escapage of.electrolyte gases from the vent hole 8 through the vent hole l0. It is still further important that the over-all length of the cylindrical cavity 6 be in excess of the height of the portion l3 to insure that the portion H be entirely free of the conical cavity 1 (as shown in Fig. 2) in order that minimum interference be offered to initial sealing of the base of the valve 3 against the inner surface of the body cap 2.

I claim:

1. A vent mechanism comprising, a body having a cylindrical cavity sealed at one end and a conical cavity in continuation of the open end of said cylindrical cavity, the sealed end of said cylindrical cavity and the apex of said conical Stated in equation form,

cavity, each having a vent hole, and a sealing element having a cylindrical portion and a truncatedconical portion with surface elements in respective parallelism with the surface elements of said combined cavities, the over-all length 01 said cylindrical cavity being greater than the over-all length of the cylindrical portion of said sealing element such that the latter is adapted to have sliding motion within said combined cavities.

2. A vent mechanism comprising, a body having a shallow cylindrical cavity sealed at one end and a conical cavity in continuation of the open end of said cylindrical cavity, said conical cavity having a vent hole at its apex and longitudinally disposed grooves communicating therewith, the sealed end of said cylindrical cavity being provided with a centrally disposed vent hole, and a sealing element having a cylindrical portion and a truncated conical portion with surface elements in respective parallelism with the surface elements of said combined cavities, the over-all length of said cylindrical cavity being greater than the over-all length of the cylindrical portion of said sealing element such that the latter is adapted to have sliding motion within said combined cavities.

3. A vent mechanism comprising, a body having a shallow cylindrical cavity sealed at one end and a conical cavity of approximately equal base and altitude in continuation of the open end of said cylindrical cavity, said conical cavity having a vent hole at its apex and longitudinally disposed grooves communicating therewith, the sealed end of said cylindrical cavity being further provided with a centrally disposed vent hole, and a sealing element having a cylindrical portion and a truncated conical portion with surface elements in respective parallelism with the surface elements of said combined cavities, the over-all length of said cylindrical cavity being greater than the over-all length of the cylindrical portion of said sealing element such that the latter is adapted to have sliding motion within said combined cavities.

EARL R. GIESEMAN. 

